English
The product of two order-bornologies is an order-bornology.
Русский
Произведение двух борологий порядка образует борологию порядка.
LaTeX
$$$\operatorname{IsOrderBornology}(\alpha \times \beta)$$$
Lean4
instance instIsOrderBornology {β : Type*} [Preorder β] [Bornology β] [IsOrderBornology β] : IsOrderBornology (α × β)
where
isBounded_iff_bddBelow_bddAbove
s := by
rw [← isBounded_image_fst_and_snd, bddBelow_prod, bddAbove_prod, and_and_and_comm, isBounded_iff_bddBelow_bddAbove,
isBounded_iff_bddBelow_bddAbove]